The Synthesis and Absorption Character of New Bis（dithiobenzil）nickel Complex NIR Dyes

A series of new NIR dyes bearing 4-(4-morpholinyl) phenyl and substituted phenyl,were synthesized. The maximum absorption wavelengths of these dyes range from 928nm to 990nm.     

Synthesis and Herbicidal Activities of 3-（Substituted phenyl）isoxazole Derivatives

Several novel 3-(substituted phenyl)isoxazole derivatives were prepared from phenyl butan-l,3-dione. Their structures were confirmed by IH NMR, 1R, and CIMS. Preliminary bioassay showed that some of them exhibited good activities toward various weeds.     

Organic Reactions in Ionic Liquids： Ionic Liquid-promoted Efficient Synthesis of Disubstituted and Trisubstituted Thioureas Derivatives

In ionic liquid [Bmim][BF4], a series of disubstituted and trisubstituted thiourea derivatives were synthesized from phenyl and butyl isothiocyanate with a variety of amine in excellent yield.     

Theoretical Study on the Mechanism of Sonogashira Coupling Reaction

The mechanism of palladium-catalyzed Sonogashira cross-coupling reaction has been studied theoretically by DFT （density functional theory） calculations. The model system studied consists of Pd（PH3）2 as the starting catalyst complex, phenyl bromide as the substrate and acetylene as the terminal alkyne, without regarding to the co-catalyst and base. Mechanistically and energetically plausible catalytic cycles for the cross-coupling have been identified. The DFT analysis shows that the catalytic cycle occurs in three stages： oxidative addition of phenyl bromide to the palladium center, alkynylation of palladium（Ⅱ） intermediate, and reductive elimination to phenylacetylene. In the oxidative addition, the neutral and anionic pathways have been investigated, which could both give rise to cis-configured palladium（Ⅱ） diphosphine intermediate. Starting from the palladium（Ⅱ） diphosphine intermediate, the only identifiable pathway in alkynylation involves the dissociation of Br group and the formation of square-planar palladium（Ⅱ） intermediate, in which the phenyl and alkynyl groups are oriented cis to each other. Due to the close proximity of phenyl and alkynyl groups, the reductive elimination of phenylacetylene proceeds smoothly.     

Catalytic Asymmetric [2, 3]－Sigmatropic Rearrangement of Sulfur Ylides Generated from Carbenoids and Allenic 2－Methylphenyl Sulfide

The first investigation on catalytic asymmetric [2,3]-sigmatropic rearrangement of sulfur ylides generated from carbenoids and allenic phenyl sulfide was carried out. Up to 55% ee value was obtained.     

Microbial reduction of sulfur-containing ketones by Geotrichum sp.

Bioreduction of some β-carbonyl phenyl sulfides, sulfoxides and sulfones (1, 3, 5, 8, 11 and 13) by Geotrichum sp. was studied. Reduction of β-carbonyI phenyl sulfoxides (5 and 8) gave anti-Prelog sulfoxide alcohols. (S, Ss)-3-Chloro-1-phenylsulfinylpropan-2-ol (9) was obtained in high yield with 95% e. e. after recrystallization from methylene chloride-petroleum ether.     

Effect of Fluorination on Aggregate Structure of Perylene Diimide

The effect of fluorination on the aggregate structure of a novel fluorinated perylene diimide, N, N‘-diperfluorophenyl-3, 4, 9, 10-perylenetetracarboxylic diimide 1, was investigated by UV-Vis absorptions and the conformation simulations from AM1 semi-empirical quantum mechanics modeling. The results showed that in the solid film 1 molecules stacked with the perfluorinated phenyl groups straightly over or below the perylene cores of the adjacent 1 molecules.     

Investigation of the effect of berberines alkaloids in Coptis chinensis Franch on Bacillus shigae growthby microcalorimetry

The inhibitory effects of five berberines alkaloids (BAs) from rhizoma of Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Bacillus shigae (B. shigae) growth were investigated by microcalorimetry. The power-time curves of B. shigae with and without BAs were acquired; meanwhile, the extent and duration of inhibitory effects on the metabolism were evaluated by growth rate constants (k1, k2), half inhibitory ratio (IC50), maximum heat output (Pmax), and peak time (tp). The values of k1 and k2 of B. shigae in the presence of the five BAs decreased with the increasing concentrations of BAs. Moreover, Pmax was reduced, and the value of tp increased with increasing concentrations of the five drugs. The inhibitory activity varied with different drugs. IC50 of the five BAs was respectively 75 μg/mL for berberine, 90 μg/mL for coptisine, 115 μg/mL for palmatine, 220 μg/mL for epiberberine, and 400 μg/mL for jatrorrhizine. The sequence of antimicrobial activity of the five BAs: berberine > coptisine > palmatine > epiberberine > jatrorrhizine. The functional groups methylenedioxy at C2 and C3 on phenyl ring improve antimicrobial activity more strongly than methoxyl at C2 and C3 on phenyl ring. However, the effect of bacteriostasis is not significant with methylenedioxy or methoxyl at C9 and C10 on phenyl ring.     

Synthesis and Photocytotoxicity of Mono-functionalised Porphyrin with Valine Moiety

A mono-funtionalised tetraphenylporphyrin (TPP) bearing valine moiety at the phenyl ring was synthesized for photocytotoxicity examination in four steps, starting from regiospecific mono-nitration of TPP at the phenyl ring. The in vitro photocytotoxicitic effect against SPC-Al adenocarcinona cell line was tested.     

Polystyrene-supported Palladium(II) Ethylenediamine Complex: A Recyclable Catalyst for the Syntheses of 2-Benzyl- imidazo[2,1-b][1,3]benzothiazoles by Sonogashira Reaction

The polymer-supported palladium(II) ethylenediamine complex was used as a catalyst for the heterocyclization during Sonogashira reaction between a substituted phenyl iodide and 2-amino-3-(2-propynyl)-1,3-benzothiazolium bromide, which could readily be recovered from the reaction medium by a simple filtration, and reused without a significant loss in its activity.     

Determination of absolute photoionization cross sections of the phenyl radical

Photoionization cross sections of the phenyl radical to form the phenyl cation were measured using tunable vacuum ultraviolet synchrotron radiation coupled with photofragment translational spectroscopy. The phenyl radical was produced via 193- or 248-nm dissociation of chlorobenzene. At 10.0 eV, the photoionization cross sections for the phenyl radical averaged over product channels were found to be 13.4 +/- 2.0 and 13.2 +/- 2.0 Mb, respectively, with very little effect seen from the range of internal excitation produced at the two photolysis wavelengths. Using the photoionization cross section values for each channel, photoionization efficiency curves for the phenyl radical were placed on an absolute scale from 7.8 to 10.8 eV.     

Chemical ionization mass spectrometry of benzoyl peroxide: A radical aromatic substitution resulting in biphenylcarboxylic acid in the gas phase

A radical aromatic substitution resulting in biphenylcarboxylic acid is inferred for the decomposition of benzoyl peroxide from the chemical ionization and collision-induced dissociation mass spectra. The thermolysis of benzoyl peroxide gives rise to a benzoyloxy radical, which undergoes rapid decarboxylation and hydrogen abstraction leading to phenyl radical and benzoic acid, respectively. Attack of the resulting phenyl radical on the benzoic acid results in biphenylcarboxylic acid. On the other hand, the phenyl radical abstracts a hydrogen atom to yield benzene, which is then subjected to the attack of a benzoyloxy radical, affording phenyl benzoate. This substitution reaction rather than the recombination of benzoyloxy and phenyl radicals is found to be responsible for the formation of phenyl benzoate under the present conditions.     

A repertoire of pyridinium-phenyl-methyl cross-talk through a cascade of intramolecular electrostatic interactions

Direct intramolecular cation-pi interaction between phenyl and pyridinium moieties in 1a(+) has been experimentally evidenced through pH-dependent (1)H NMR titration. The basicity of the pyridinyl group (pK(a) 2.9) in 1a can be measured both from the pH-dependent chemical shifts of the pyridinyl protons as well as from the protons of the neighboring phenyl and methyl groups as a result of electrostatic interaction between the phenyl and the pyridinium ion in 1a(+) at the ground state. The net result of this nearest neighbor electrostatic interaction is that the pyridinium moiety in 1a becomes more basic (pK(a) 2.92) compared to that in the standard 2a (pK(a) 2.56) as a consequence of edge-to-face cation (pyridinium)-pi (phenyl) interaction, giving a free energy of stabilization (DeltaDeltaG(o)pKa) of -2.1 kJ mol(-1). The fact that the pH-dependent downfield shifts of the phenyl and methyl protons give the pK(a) of the pyridine moiety of 1a also suggests that the nearest neighbor cation (pyridinium)-pi (phenyl) interaction also steers the CH (methyl)-pi (phenyl) interaction in tandem. This means that the whole pyridine-phenyl-methyl system in 1a(+) is electronically coupled at the ground state, cross-modulating the physicochemical property of the next neighbor by using the electrostatics as the engine, and the origin of this electrostatics is a far away point in the molecule-the pyridinyl-nitrogen. The relative chemical shift changes and the pK(a) differences show that the cation (pyridinium)-pi (phenyl) interaction is indeed more stable (DeltaDeltaG(o)pKa = -2.1 kJ mol(-1)) than that of the CH (methyl)-pi (phenyl) interaction (DeltaDeltaG(o)pKa = -0.8 kJ mol(-1)). Since the pK(a) of the pyridine moiety in 1a is also obtained through the pH-dependent shifts of both phenyl and methyl protons, it suggests that the net electrostatic mediated charge transfer from the phenyl to the pyridinium and its effect on the CH (methyl)-pi (phenyl) interaction corresponds to DeltaG(o)pKa of the pyridinium ion (approximately 17.5 kJ mol(-1)), which means that the aromatic characters of the phenyl and the pyridinium rings in 1a(+) have been cross-modulated owing to the edge-to-face interaction proportional to this DeltaG(o)pKa change.     

Synthesis of aromatic polyethers by Scholl reaction. VII. Oxidative polymerization of 2,2-bis[4-(1-naphthoxy)phenyl]propane and 2,2-bis [4-(1-naphthyl)phenyl]propane

The synthesis and the mechanism of oxidative polymerization of 2,2-bis[4-(1-naphthoxy)phenyl]propane ( 4 ) and 2,2-bis[4-(1-naphthyl)phenyl]propane ( 9 ) are presented. Both monomers polymerize by two different propagation steps. The first one represents a cation-radical dimerization of the naphthyl groups to dinaphthyl structure. H⁺[FeCl₄]^? generated from the first propagation step initiates a transalkylation reaction which provides structural units containing isopropylidenic groups inserted between phenyl and naphthyl, and between two naphthyl groups, respectively. Since the phenyl groups resulted from the second propagation reaction are unreactive in both the oxidative coupling and the transalkylation steps this polymerization reaction leads to polymers with low molecular weights containing phenyl chain ends.     

无溶剂无催化剂微波促进下 1-苯基-3-甲基-5-吡唑啉酮与芳醛的反应研究

无溶剂无催化剂条件下,微波促进1-苯基-3-甲基-5-吡唑啉酮与芳醛的缩合反应选择不同辐射功率将分别得到4-芳亚甲基-3-甲基-1-苯基-5-吡唑啉酮和4,4′-芳亚甲基-双(1-苯基-3-甲基-5-吡唑啉酮),产率良好.产物结构经1H NMR,13CNMR和IR进行了表征.     

Substituent effects in the mass spectral fragmentation of aryl esters

The mass spectra of m- and p-substituted phenyl acetates, phenyl propionates, phenyl chloroacetates and phenyl fluoroacetates have been determined. The fragmentation of aryl esters is affected by acyl substituents as well as by aryl substituents. Esters having acyl groups of low ionization potential show greater changes in fragmentation because of aryl substituents than those having acyl groups of high ionization potential. Each series has a fairly definite crossover point where fragmentation changes from predominant rearrangement to predominant cleavage.     

Reactions of heterocumulenes with organometallic reagents: XIX. Quantum-chemical study on S-alkylation and intramolecular cyclization of lithiated methoxyallene adducts with methyl, phenyl, and 3-(methylsulfanyl)phenyl isothiocyanates. Concurrent formation of pyrrole and/or thiophene rings

Concurrent reaction paths leading to the formation of thiophene and/or pyrrole rings from adducts of lithiated methoxyallene with methyl, phenyl, and 3-(methylsulfanyl)phenyl isothiocyanates were simulated by quantum-chemical methods. According to the calculations, pyrrole ring closure is kinetically more favorable for the adduct of 1-lithio-1-methoxyallene with methyl isothiocyanate, both reaction channels are equally probable for the adduct with phenyl isothiocyanate, and thiophene ring closure is the main reaction path for the adduct with 3-(methylsulfanyl)phenyl isothiocyanate.     

Thermal rearrangement of {[2-(Arylmethylene)cyclopropyl]methyl}(phenyl)sulfanes and selanes

{[2-(Arylmethylene)cyclopropyl]methyl}(phenyl)sulfanes and {[2-(arylmethylene)cyclopropyl]methyl}(phenyl)selanes, generated in situ from 2-(arylmethylene)cyclopropylcarbinols with sodium benzenethiolate and sodium benzeneselenolate, could undergo rearrangement upon heating to afford (2-arylmethylidenebut-3-enyl)(phenyl)sulfanes and (2-arylmethylidenebut-3-enyl)(phenyl)selanes, in good to excellent yields as mixtures of E- and Z-isomers, respectively. A radical rearrangement was proposed on the basis of control experiments for this process.     

The Ireland-Claisen rearrangement as a probe for the diastereoselectivity of nucleophilic attack on a double bond adjacent to a stereogenic centre carrying a silyl group

The E- and Z-silyl enol ethers 4 derived from allyl 3-R-3-dimethyl(phenyl)silylpropanoate (R = Me, Pr(i) and Ph) and the Z-silyl enol ethers 7 derived from 4-R-4-dimethyl(phenyl)silylbut-2-enyl acetate (R = Me and Pr(i)) undergo Ireland-Claisen rearrangements largely in the same stereochemical sense, with C-C bond formation taking place anti to the silyl group in the conformations 22, 23 and 24 in which the hydrogen atom on the stereogenic centre is inside, more or less eclipsing the double bond. The E-silyl enol ether E-7a derived from 4-methyl-4-dimethyl(phenyl)silylbut-2-enyl acetate shows low diastereoselectivity in the alternative sense, probably because C-C bond formation takes place anti to the silyl group in the conformation 26 with the methyl group inside, but the silyl enol ether E-7b derived from 4-isopropyl-4-dimethyl(phenyl)silylbut-2-enyl acetate shows low diastereoselectivity in the normal sense. The E- and Z-silyl enol ethers 33 derived from cis-crotyl 3-phenyl-3-dimethyl(phenyl)silylpropanoate and the E-silyl enol ether 39 derived from trans-crotyl 3-phenyl-3-dimethyl(phenyl)silylpropanoate undergo Ireland-Claisen rearrangements largely in the same stereochemical sense as their allyl counterparts, but with moderately high levels of diastereocontrol in setting up the third stereogenic centre following from chair-like transition structures.     

Thermal degradation of phenyl methacrylate-methyl methacrylate copolymers

The degradation behaviours of poly(phenyl methacrylate), four phenyl methacrylate-methyl methacrylate copolymers which span the composition range, and poly(methyl methacrylate) have been compared by using thermogravimetry in dynamic nitrogen and thermal volatilisation analysis (TVA) under vacuum, with programmed heating at 10°C/min. Volatile products have been separated by subambient TVA and identified and the cold ring fraction and partially degraded polymer have been examined by ir spectroscopy. Poly(phenyl methacrylate) resembles poly(methyl methacrylate) in degrading completely to monomer. Copolymers of phenyl methacrylate and methyl methacrylate are more stable than the homopolymers. On degradation, the major products are the two monomers. Minor products from all the copolymers include carbon dioxide, dimethylketene, isobutene and formaldehyde. Copolymers with low and moderate phenyl methacrylate contents show the formation of anhydride ring structures in the cold ring fraction and partially degraded copolymer, together with small amounts of methanol in the volatile products. Carbon dioxide is a more significant product at lower phenyl methacrylate contents.The mechanism of degradation is discussed.